In fact, every search engine of its database will be regularly updated to ensure that the latest search results.    Their only update each cycle is different.    However, due to the Google search engine as a leader and has tremendous influence, and we update it more attention.    Google's update process, the index always changing, so it's search results will also be of great change.    Pages Rating (PageRank), and to return to the links in the update is completed during this period.    Is not only the search results to be updated? Fact is not the case.    Any update process is complete, Google search results pages Position will have some changes.    On the one hand, this is because Google's Web spiders (spider) has been in the activities and continuously discover new sites; on the other hand is because once the network spider detected failure of those "dead" sites, these sites will be from the list of Index delete.    Google Dance in the process, Google's Robot has been included on each site re-iteration, the calculation of its links and Related few, and the value of these links assessment.    Then in accordance with its PageRank system to calculate the PageRank value of each page, based on that figure again to re-arrange the various sites in the list position.    Because Google always traversal and update its selection of pages, and therefore its search results in this month will have a slight change.    However, only in the Google Dance during their search results will have a larger change.    You have to take into account Google has eight data centers, with more than 10,000 Taiwan-sharing servers.    For some reason, Google updated Although the index list in the next few days to complete, but the results of the search continued for a month will be updated.    Whether it's Google or other search engines, search throughout the update of the list are essential.    These ongoing increase in the update, at any one time, the index would only affect part, but not all. 
  How to check Google Dance? Google has eight major online WWW server network, they are 
  1. Www-ex.google.com - (that we normally used www.google.com) 
  2. Www-sj.google.com - (can be entered through www2.google.com) 
  3. Www-va.google.com - (can be entered through www3.google.com) 
  4. Www-dc.google.com 
  5. Www-ex.google.com6. Www-in.google.com 
  7. Www-zu.google.com 
  8. Www-cw.google.com 
  Google Dance in the process, you can check it on page 8 in the Google Web server.    They show a certain period of time would be more the result of the different, as if in the same dance.    For this reason, their update process has been referred to as the "Dancing / dance", so there will be a Google Dance name.    Want to see whether Google Dance course, the most straightforward approach is to do a search www.google.com.    At the top of Google's search results pages of the blue, this information will be displayed: "A total of 626,000 of the search results, this is the first of 1-10. Search by 0.48 seconds when." Then you then www2.google. com and www3.google.com done on the same conditions as if the draw for the same number of different search results, it shows that Google is updated.    Of course, you can also view all of the eight listed above web site.    Www2 fact is www-sj, www3 is www-va.    It must be noted that in the url column for admission of the complete address www-extension. Google.com can get the correct test results.    There are also some web site to provide such a tool, this allows you to the eight data centers to check search results at the same time, and compare query results.    If in the above eight at the search results are ranked number and the same, it would show that Google's update process has been completed.    Google Dance importance: For most people, Google's update process for them is not important.    However, for any one身处search engine optimization industry people, this is a notable period of time.    First, the Google Dance period, we always received a lot of telephone customers, saying that they could not find on Google has its own website.    In fact, this is temporary.    But sometimes the situation can be sustained day, it will cause for panic.    When these pages in the re-emergence of Google, their ranks have been more forward than the original.    This is the only calm people's fears.    See that the search engine is the importance of this can not but that is a very interesting thing.    Google Dance Technical Background: Google's search results from the network server many as ten thousand.    This means that when you type in a Google or enquiries by many as ten thousand this in a server to handle your query request.    And it must be far less than one second of time for your response (to the query results you want).    Just imagine it, which seems to us to the National Library, all the books-on into an airport, and then search for the "Art of War", the aim is to Yizhawen time will be able to find the correct results.    -- Almost unimaginable, is not it?    But do not forget, we are such a day in the search engine search on the things we want.    Google uses a Linux server.    Google in the process of updating its index, its eight data centers will be updated many as ten thousand servers.    Of course, from an index to a index will always be some changes.    It is simply because there is always a new page is added in, at the same time some of the content of the website will also be changes in the search results on their rankings change.    But Google Dance in the process, these changes are very dramatic.    The Index will be transmitted to the division after these servers, these servers were updated, until eventually all these servers to update the index to a new database.    Google Dance and DNS (domain name server): Google's index results from eight different data provided by the Centre.    In this eight data centers including many as ten thousand network servers, the data center is being placed in the United States.    Google uses a variety of data center faster on the end-user response to the search request.    If you want to enter a physical to the closure of your data center, then in theory you need fewer links to the jump point, or you need to experience fewer internal node to get into the data center, and to return to your own address.    Each data center has its own IP address (the number of addresses on the Internet), by the DNS (domain name server) of these IP addresses access path management.    DNS system can be immediately on your request routing to your nearest or lighter load that data centres.    Then by the data center that you will visit idle easily routing to a server.    In this way, through the use of Google DNS list, a two-step approach to the transmission of the load balanced.    And the visit of the internalization of the management, so as to shorten the distance data transmission, and improved response to the request of the search speed.    Google Dance in the process, eight data centers is not all servers can also accept the new index.    In fact the new index can only be transmitted to each separate data centers, the division has been followed by every part of each transmission to the data center.    Segmentation of the different at different times been uploaded to the server for each group so that will affect the search results. 

  Google Dance in the process, if users query on Google, they may be in the minutes of the query results from a part or all of its data has not been updated data centre, and a few minutes later from another a data centre to be updated after the data.    However, from a user's perspective, this change occurred in less than one minute.    Search engine every month for about a new indexing, but it also lead to a result has created a lot of problems.    After all, the search engines to thousands of billions of documents traversal and indexing, and then compiled the results of its data processing into a coherent unit, which is a small project.    Even after Google Dance, in the search results, there may be some smaller fluctuations.    This is due to different data centers in the index is not the same as in those.    The addition of new sites, waste sites to delete, and so on.    It is estimated that every day there will be at least 8 million new website generation, some of which were added to search engines, thereby affecting the search results.    Now, if you want to look at Google by its Google Dance under the definition of the relevant pages can visit their www.google.com/googledance2002.    Very interesting and worth a look!